lecture 14 - biostatistics III Flashcards
What is the equation for the standard error of a sample?
SE=s/squareroot(n), where s is the sample standard deviation and n is the sample size
What is a confidence interval?
A range around the sample mean plus or minus 1.96*SE from the mean. For repeated sampling, we could be 95% confident that the true population mean lies between the upper and lower confidence limit
What is the equation for the confidence limit (upper or lower limit)?
limit= x ± 1.96 * SE, where x is the sample mean
If sample size is increased, what will happen to the confidence interval?
The width of the confidence interval decreases, so we can be more confident
What is sampling error?
A statistical error that happened due to the selected sample not perfectly representing the population of interest. Can increase variability and therefore make the results more uncertain.
What is non-sampling error?
Error that arises from errors arising during data collection/conducting the survey. Can move us away from the truth - i.e. drawing the wrong conclusions.
What is the sampling distribution centred on?
The population mean
